Means for dispensing and locking a safety strap



Dec. 28, 1965 J. w. L. PETTY 3,226,053

MEANS FOR DISPENSING AND LOCKING A SAFETY STRAP Filed Oct. 14, 1963 4Sheets-Sheet 1 /NVEN7DR JOHN WILLIAM LEMMRI) ?5TTY A TTORNEYS Dec. 28,1965 J. w. PETTY 3,226,053

MEANS FOR DISPENSING AND LOCKING A SAFETY STRAP Filed Oct. 14, 1963 4Sheets-Sheet 2 117 PM km km ZZZ IOQ

//v VEN 7011 JOHN WILL/AM EDkMRD P1117) A r TOR A/EYs Dec. 28, 1965 J,w. 1... PETTY 3,

MEANS FOR DISPENSING AND LOCKING A SAFETY STRAP Filed Oct. 14, 1963 4Sheets-Sheet 3 INVENTOK A 770/2 NEYS Dec. 28, 1965 .1. w. 1.. PETTY3,226,053

MEANS FOR DISPENSING AND LOCKING A SAFETY STRAP Filed Oct. 14, 1965 4Sheets-Sheet 4 I 1 A g ;-108 F158. 110 111120 111 110 II" I III Fig.9.

/NVENTOR jg/ (JILL/AM LEM/14E) 7 57-9! mizm A 7'TORNEKS' United StatesPatent 3,226,053 MEANS FOR DISPENSHNG AND LOCKING A SAFETY STRAP JohnWiliiam Ledward Petty, Haywards Heath, England, assignor to NorrisBrothers Limited, Haywards Heath, England, a British company Filed Oct.14, 1963, Ser. No. 316,031 Claims priority, application Great Britain,Oct. 15, 1962, 38,999/62; May 18, 1963, 19,872/63 Claims. (Cl. 242107.4)

This invention is for improvements in or relating to the mounting uponany type of vehicle means for dispensing and locking a safety strap.

The main object of the present invention is to produce means to beassociated with seat safety straps or harness and dispensing meanstherefor whereby said straps or harness become locked irrespective ofthe behaviour of the occupants of the seats who are wearing said strapsor harness. It is an inherent weakness of a great number of so-calledlocking devices that said devices only become effective to lock thestrap when the wearer is thrown violently forwards. Other safety strapsor harness do not incorporate any form of strap-dispensing device (whichat least permit complete or partial freedom of movement provided suchmovement is gradual and not suddent) and such safety straps or harnessare objectionable in that they severely restrict the wearer.

The present invention will now be more particularly described withreference to the accompanying diagrammatic drawings in which:

FIGURE 1 illustrates diagrammatically in side elevation and partly insection one embodiment of the present invention;

FIGURE 2 illustrates a section along the line IIII of FIGURE 1;

FIGURE 3 is a plan view of an alternative embodiment of the presentinvention with the top half of a twopart cover removed and with thesafety strap fully extended;

FIGURE 4 is a section along the line IV-IV of FIG- URE 3;

FIGURE 5 is a section along the line V-V of FIG- URE 3;

FIGURE 6 is a section along the line VI-VI of FIG- URE 3;

FIGURE 7 is a section along the line VII-VII of FIGURE 3;

FIGURE 8 is a section along the line VIIIVIII of FIGURE 3;

FIGURE 9 is a view similar to that of FIGURE 6, but showing verticalmounting of the apparatus with the bobweight having through the tappetcaused the pawl to engage the ratchet teeth; and

FIGURE 10 is a view of cap 58 after removal from the remainder of theapparatus and seen looking in the direction of the arrow C in FIG. 1,without any of the parts mounted on spindle 53.

Referring to FIGURES 1 and 2, there is shown a rotatable means or drum40 upon which a safety belt is adapted to be Wound, said drum beingmounted for rotation in a casing 41 which encloses a space 42 in which areeledup safety belt is housed. Said casing 41 would be provided with aslot (not illustrated) through which the belt would extend formanipulation by the wearer. A disc or collar 43 is fixed to the drum 40and carries three pawls 44 (FIGURE 2) each of which is mounted thereonfor rocking movement about an axis C (see FIGURE 1) and each of which isformed with a follower 45. The drum 40 is formed with threecircumferential slots through which the various followers 45 extend. Inradial alignment with the set of pawls 44 is an annulus of ratchet teeth47 of which only some have been illustrated in FIGURE 6, it beingunderstood that there is a continuous succession of such teeth. Saidteeth 47 are illustrated as having been formed in the casing 41 itselfbut there are obviously numerous other ways of achieving the sameresult.

A cam consisting of a right circular conical head 48 and a stem 49 ismounted in a bearing 50, the flanges of which are securable to an endface of the casing 41 by means of screws 51. It is the head 48 and thestem 49 which have been omitted for the sake of clarity in FIG- URE 2.Against that end of the stem 49 which protrudes from the casing 41 thereis arranged a bell crank lever 52 which takes the form of a triangularplate which is mounted for rocking movement about the axis of a spindle53 mounted in bosses F and E formed on cap 58, the edge 54 of thetriangle illustrated being normal to the edge 55. A freely suspendedbob-weight 56 is supported by a plate 57 which is capable of adjustmentabout the axis of the spindle 53 by conventional means not shown, theends of which are carried by or supported upon a cap 58 which isrotatable about the axis D about which the drum 40 rotates.

Cap 58 is secured to casing 41 by radially inwardly projecting ridge Aformed in the cap 58 to mate with a groove formed in an axiallyextending element B formed in the casing 41.

It will be seen that when, due to acceleration, deceleration and/ orchange of attitude of the apparatus, the bob- Weight 56 moves relativelyto the lever 52, the stem 49 will be moved axially along the hollow drum40 and the head 48 (against which the radially innermost portions of thefollowers 45 bear) will cause the pawls 44 to move in an aresubstantially radially outwardly into engagement with three teeth 47.Since the casing 41 is, in use, directly or indirectly fixed to animmovable part of a vehicle,

it will be obvious that with the pawls engaging said teeth the drum 40is locked against rotation.

Each of the pawls is lightly spring-biassed in such a manner as to tendto return to the positions thereof illusv trated in FIGURE 2, as by aspring 59 anchored at one end to the follower 45 and at the other end toa stud 60 on the disc 43. This will prevent engagement of the pawls 44with the teeth 47 under the action of centrifugal force.

The cap 58 and, therefore, the attitude of the spindle 53 has been madeadjustable because the axis D may be kept horizontal but the casing as awhole may need to be rotated about said axis D before being fixed to thevehicle (for example if the slot through which the belt extends isdesired to face the front of the vehicle rather than the roof thereof).Subsequent adjustment of the cap, which could have a line or arrowpainted thereon normal to the axis of the spindle 53, will ensure thatit will be readily seen whether or not the bob-weight 56 is properlyfreely suspended.

Lastly, if in a particular vehicle it is necessary to mount the casing41 in such a manner that the axis D is inclined at an angle between thehorizontal and the vertical, it would merely be necessary to substitutethe appropriate triangular plate in which the edge 55 i in contact withthe stem 49 and the edge 54 is horizontal, the plate 57 also beingadjusted about the axis of the spindle 53 to bring the flat surface ofthe bob weight 56 into contact with said edge 54. If the axis D is to bevertical, the flat surface of the bob weight 56 could act on the end ofthe stem 49 itself without the interposition of the bell crank lever 52.

Referring now to FIGURES 3 to 9, there is illustrated an inner belt tube70 (FIGURE 4) which is inserted into a sewn loop 71 formed at one end ofa safety belt or strap 72. An outer belt tube 73 is slipped around theloop 71 within which is the tube 70, the strap 72 extending through anaxially extending slot 74 (FIGURES 6 and 8). This serves to anchor thesafety belt to the apparatus.

One end of the tube 73 is formed with a pair of axially extendingnotches 75, 76 (FIGURE 6). The tongues of metal which between themdefine these notches 1 and the slot 74 (clearly seen in FIGURE 6) serveto connect the tube 73 drivingly to a wheel 77 having formed therein aplurality of ratchet teeth 78. A bush 79 in the centre bore of the wheel77 encircles a shaft 80 which extends through the tube 70. A second bush81 is inserted into the other end of the tube 73, and said other end oftube 73 has a portion 82 thereof which serves as an anchorage and whichis formed by radially outward deformation of a part of said other end.There is also a notch 83 (FIGURE 7) extending axially from said otherend. One hooked end 84 of a coil spring 85 is inserted in the notch 83and engages the anchorage 82 whilst the other end of said spring iswrapped around a shaft 86 whichis parallel to the shaft 80.

The shaft 86 is formed over a portion of its length with closely spacedsplines 87' and is provided at its end 88 with a flat (not illustrated),said end being, therefore, D-shaped for a purpose hereinafter explained.A bob-weight support indicated generally by 89 consists of a one-piecemoulding (in nylon preferably) with an arm 90 in which there is a hole91 through which there extends the neck 92 of a bob weight 93 having asubstantially hemispherical head 94 and a mass 95 (FIGURE 6). Thesupport 89 is preferably made of a tough natural or synthetic resinmaterial because the intention is for said support to be keyed to theshaft 86 by reason of the splines 87 digging into said material as thesleeve part of said support 89 is rammed along the shaft. The bob weight93 is suspended freely from the arm 90.

Adjacent the support 89 is a pawl-and-tappet assembly which consists ofa pawl 96 (FIGURES and 9) secured to a bush 97 and of a one-piece tappet98 and sleeve 99, a bolt 100 being adapted to engage screw threadsformed in said tappet 98 and in a tail portion 101 of said sleeve 99 soas to tighten said sleeve on to said bush 97. The radially outer surfaceof the bush 97 and the radially inner surface of the sleeve 99 arepreferably lightly grooved or scored so as to provide mating surfaceswhich will bind or bite together all the more strongly.

Referring for example to FIGURE 6, it will be seen that the tappet 98rests upon the flat top of the substantially hemispherical head 94 ofthe bob weight 93. If the mass 95 were to move in an arc in anydirection (for example towards the viewer out of the plane of the sheetof paper) a portion of the rim of the flat top of the hemispherical head94 will move to a higher point than that occupied by that portion or anyother portion of said rim. The result of this is that the tappet 98 islifted (FIGURE 6) thereby simultaneously causing the tip of the pawl 96to cut or move across the imaginary line which defines the pitch circlealong which the tip of each tooth of the ratchet wheel would move ifthat tooth were to make a complete revolution about the axis of theshaft 80. Any pull on the safety belt will, therefore, cause the pawl 96to engage the relevant tooth 78 fully.

The ends of the shafts 80 and 86 extend through apertures formed in linkplates 102 and 103 located at opposite sides of the apparatus (FIGURES3, 5 and 6). Said link plates 102, 103 together with the spaced limbs104 and 105 of a mounting bracket 106, through which limbs said shaftsalso extend as can be seen in FIGURE 5 for example, not only ensure thatshaft spacing but also the weight of the pieces of apparatus describedabove are maintained and supported, respectively, by components strongenough to do so and not by either half of a two-part dust coverindicated generally by 107.

A thick plate 108 is located between the two limbs 104, 105 for thepurpose of stiffening this part of the apparatus and said plate 108 andthe bracket are bored to receive the shank of a bolt 109 by means ofwhich the bracket 106 is secured to the floor, door pillar, parcel shelfor the like of the vehicle. As seen in FIGURE 8, the bracket 106 is alsobored at 110 and the plate 108 is likewise bored and threaded as at 111(or provided with captive nuts as an alternative) to cater for screws(not illustrated) being screwed upwardly through the car floor intoengagement with said screw threads 111.

The shafts 80, 86 are secured at their ends by washers 112 and screws orbolts 113 the threaded shanks of which extend into threaded axial boresformed in the ends of the shafts (see FIGURE 4 for example).

The dust cover 107 is preferably formed, as stated above, in two parts.Referring to FIGURES 5 and 7, an upper part 114 and a lower part 115 areillustrated therein, the line along which the two parts meet or are incontact with one another being coincident with the axis of the shaft 86in FIGURE 5 and with the line joining the axes of the shafts 86 and inFIGURE 7. Each part 114, 115 is so shaped as to define a rectangularcavity 116 (FIGURE 3) in which is housed the shaft 86 and the majorportion of the pawl and tappet assembly descirbed above. Further, eachpart 114, 115 is so shaped as to define two spaced cavities 117 and 118,the ratchet wheel 77 being housed in the cavity 117 and the coil springbeing housed in the cavity 118. The safety belt or strap 72 is wound upon the springbiassed shaft 80 and is located between the parts of thedust cover which define said cavities 117, 118 and is not housed withinthe dust cover (see FIGURES 3, 4 and 7).

The upper part 114 is connected to the lower part 115 after theapparatus has been assembled and adjusted (as hereinafter explained) tosuit the users requirements in the following manner. The lower part 115is made with a screw-receiving boss 119 (FIGURES 3 and 8) which isprovided with a bore 120. The upper part 114 is made with a similarscrew-receiving boss 121 which is provided with a bore 122 of the samediameter as that of the bore 120 and with a bore 123 of larger diameterthan that of the bore 122, the bores 122 and 123 being axially alignedand connected with one another. A self-tapping screw 124 is screwed intothe aligned bores 120, 122 (the preferred material from which the twoparts 114, 115 of the dust cover are made being polystyrene), the headof said screw 124 being accommodated within the confines of the bore 123(FIGURE 8).

The adjustments referred to above are as follows:

The bob-weight support 89 is rammed along the shaft 86 so as to engagepositively with the splines 87 in such a manner that the arm of saidsupport 89 will be horizontally disposed when the whole apparatus ismounted in the vehicle. This is essential since the bob weight 93 mustbe freely suspended.

The position occupied by the tip of the pawl 96 relative to the teeth 78of the wheel 77 must be set accurately. Referring for example to FIGURE6, it will be obvious that, if the tip of the pawl 96 is moved in ananti-clockwise direction about the axis of the shaft 86 away from theratchet teeth 78, the forces acting upon the bob weight 93 to causeengagement of one of said teeth 78 by said pawl will have to reach apredetermined and higher value before such engagement will take placethan said forces will need to reach to ensure such engagement with thepawl 96 in the position shown in FIGURE 6. Said forces may be due toacceleration, deceleration or change of attitude (for example corneringat high but constant speed). This adjustment of the position to beoccupied by the tip of the pawl relative to the teeth 78 is achieved bythe adjustability of the tappet 98 and its integral sleeve 99 and thetightening bolt therefor relative to the bush 97 because the pawl 96 isbalanced in itself and would always tend to assume horizontaldisposition about the axis of the shaft 86 and is only constrained tokeep clear of said teeth 78 by virtue of the counterbalance provided bythe tappet 98.

In FIGURES 6 and 7, it will be seen that the apparatus is mountedhorizontally (that is, with the line joining the axes of the shafts 86and 80 horizontal) and that the bob weight is freely suspended. InFIGURE 9 the apparatus is mounted vertically (that is, with the linejoining said shaft axes vertical) and the bob weight 93 has been drawnin a displaced condition to illustrate engagement of the pawl with aratchet tooth. It will, however, be obvious that in a rest condition thebob weight 93 would be freely suspended. Intermediate mounting positionsof the apparatus can also be effected with appropriate adjustments ashereinbefore explained since the relative positions of the pawl 96 andthe tappet 98 are infinitely adjustable as also are the relativepositions of the shaft 86 and the bob weight support 89.

It will further be appreciated that the mechanism transmits only a pilotsignal or instruction to the pawl 96. Once said signal is such as tocause engagement of the pawl tip of the ratchet tooth, any pull exertedon the safety belt 72 will cause the pawl to engage said tooth fully,thereby moving into a position such as has been illustrated in FIGURE 9.

Lastly, the head 94 of the bob weight is effectively, a cam which actson the tappet 98. Thus, the flat top to said head is not a criticalfeature of the invention. Said head may have for example a conical top,the tappet 98 resting on the apex of the cone. In such a case, anymovement of the freely suspended bob weight out of its vertical restcondition would cause the tappet 98 to drop and the pawl 96 would engagea ratchet tooth and, therefore, the various parts of the apparatus wouldmerely need to be disposed in alternative positions relative to theratchet wheel 77 to be effective.

What I claim as my invention and desire to secure by Letters Patent ofthe United States is:

1. An apparatus for dispensing and locking a safety belt, comprising aframe, first and second spaced parallel shafts mounted in said frame, arotatable drum mounted on said first shaft upon which said safety beltis adapted to be mounted, a plurality of ratchet teeth mounted on oneend of said drum, pawl means pivotally mounted on the second shaftoperable to engage said teeth but normally disengaged therefrom, meansfor adjusting the position of the pawl means relative to the teeth,actuating means operating said pawl means, said actuating meansincluding an inertia operated weight, arm means mounted on said secondshaft normally substantially vertically suspending said weight forpivotal movement, said weight moving by inertia to operatively engageand pivot the pawl means into engagement with said ratchet teeth, andmeans for securing said frame in operative position on a base.

2. The apparatus as claimed in claim 1 wherein said pawl means isnormally pivotally balanced in disengaged position on said second shaft.

3. An apparatus as claimed in claim 1, wherein the axis about which saidpawl means is arranged to pivot is horizontal.

4. An apparatus as claimed in claim 1, wherein spring means areconnected to said rotatable drum.

5. An apparatus as claimed in claim 1, wherein said rotatable drum isrotatable about a horizontal axis.

References Cited by the Examiner UNITED STATES PATENTS 2,650,655 9/1953Neahr et al 242107.4 X 2,708,555 5/1955 Heinemann et al. 242107.42,708,966 5/1955 Davis. 2,825,581 3/1958 Knight 242-107.4 X 2,923,4922/1960 Walpole et a1 242-107.4

MERVIN STEIN, Primary Examiner.

1. AN APPRATUS FOR DISPENSING AND LOCKING A SAFETY BELT, COMPRISING AFRAME, FIRST AND SECOND SPACED PARALLEL SHAFTS MOUNTED IN SAID FRAME, AROTATABLE DRUM MOUNTED ON SAID FIRST SHAFT UPON WHICH SAID SAFETY BELTIS ADAPTED TO BE MOUNTED, A PLURALITY OF RATCHET TEETH MOUNTED ON ONEEND OF SAID DRUM, PAWL MEANS PIVOTALLY MOUNTED ON THE SECOND SHAFTOPERABLE TO ENGAGE SAID TEETH BUT NORMALLY DISENGAGED THEREFROM, MEANSFOR ADJUSTING THE POSITION OF THE PAWL RELATIVE TO THE TEETH, ACTUATINGMEANS OPERATING SAID PAWL MEANS, SAID ACTUATING MEANS